surface density

{
  "id": "NISTq31",
  "unitsml_id": "q:surface_density",
  "name": "surface density",
  "names": [
    {
      "value": "surface density",
      "lang": "en"
    },
    {
      "value": "areic mass",
      "lang": "en"
    },
    {
      "value": "masse surfacique",
      "lang": "fr"
    }
  ],
  "short": "surface_density",
  "type": "derived",
  "dimension": {
    "id": "NISTd51",
    "name": "surface density",
    "expression": "L-2·M",
    "components": [
      {
        "key": "length",
        "symbol": "L",
        "power": -2
      },
      {
        "key": "mass",
        "symbol": "M",
        "power": 1
      }
    ],
    "dimensionless": false
  },
  "units": [
    {
      "id": "NISTu27p10'3.u1e-2/1",
      "name": "kilogram per square meter",
      "symbol": "kg/m²"
    }
  ],
  "unit_count": 1,
  "identifiers": [
    {
      "type": "nist",
      "id": "NISTq31"
    },
    {
      "type": "unitsml",
      "id": "q:surface_density"
    }
  ],
  "references": [
    {
      "type": "normative",
      "authority": "si-digital-framework",
      "uri": "http://si-digital-framework.org/quantities/SUDE"
    },
    {
      "type": "informative",
      "authority": "qudt",
      "uri": "http://qudt.org/vocab/quantitykind/AreaMass"
    }
  ]
}